This CPU is built in my Apple IIgs computer from 1986.
The 65C816 is a fully static CMOS 16-bit microprocessor featuring software compatibility with the 8-bit
NMOS and CMOS 6500-series predecessors. It extends addressing to a full 16 megabytes. A software switch determines whether the processor is in the 8-bit "emulation" mode, or in
the native mode, thus allowing existing systems to use the expanded features.
References:Datasheet (WDC equivalent)